sa toyota corolla na plastic top radiator, some roadside shops can fabricate a copper version nun. WALANG pamalit na plastic din....they would recommend replace the radiator lagi.
A cheaper "temporary" alternative is the radiator repair resin sold sa mga DIY shops (like ACE)...parang gladiator yata yung brand.
Merun pang isa na pang temporary fix (pero I have forgotten the name) na parang yung gladiator din pero ibang brand.
The important thing is when you use this resin fix...you just remove water from radiator and make sure that the portion to be repaired is clean and dry.
After applying the resin...wait for it to cure (depende sa brand it is anywhere between 30 mins to 3 hours). pagnag-cure na, that's the time pa lang lagyan ulit ng tubig and use. These resins have a curing time for the proper polymerization of the chemicals. Violate this curing time, then you will have a weak hold.
If properly cured na it should hold until you finally find a better replacement (or worst this could be the real fix na).